Immunosuppressive activity and polyamine levels of seminal plasma in azo-ospermic, oligospermic, and normospermic men.

Seventy specimens of human seminal plasma obtained from azo-ospermic, oligospermic, and normospermic men were tested for immunosuppressive activity on normal donor lymphocytes. Spermine and spermidine levels in acidic extracts were determined in 32 specimens of seminal plasma from the three groups. The original seminal plasma as well as the neutralized spermine extracts were examined for their effect on the functional activity of the lymphocytes. Seminal plasma obtained from the normospermic and oligospermic semen showed significant immunosuppressive activity, whereas no immunosuppressive activity was induced by seminal plasma from azo-ospermic semen. The latter finding was in accordance with the low spermine levels in azo-ospermic semen, which were about 50% of those found in normospermic and oligospermic seman. Acidic extraction of the seminal plasma of azo-ospermic origin resulted in an increase in spermine levels and also in immunosuppressive activity, demonstrating that in azo-ospermic men spermine is bound probably to a protein and is released after acidification, exerting its immunosuppressive activity only when unbound.